Date of Graduation

Document Type

Degree Name

Degree Level

Department

Advisor

David M. Miller

Committee Member

Kristofor R. Brye

Second Committee Member

Lisa S. Wood

Third Committee Member

Erik D. Pollock

Keywords

Biological sciences, Health and environmental sciences

Abstract

In 2013, only 37% of the 32 million Mg of flue gas desulfurization (FGD) by-products generated in the United States were reused beneficially. If FGD by-products could be used as a beneficial soil amendment, millions of megagrams may be diverted away from surface impoundments and landfills. The purpose of this research was to identify the liming characteristics of a high-Ca dry FGD (DFGD) by-product in comparison to a Class-C fly ash (FA) and reagent-grade CaCO3, and to evaluate the effects of land application to a managed grassland on runoff, plant, and soil quality. Liming characteristics were determined by measuring the calcium carbonate equivalence (CCE), degree of fineness (DOF) and calculating the effective neutralizing value (ENV). The DFGD by-product was land-applied to a managed grassland in May 2015 and runoff, plant, and soil samples were collected over a 12-mo period. The ENV of 79.4% for the DFGD by-product was lower (P < 0.05) than that of reagent-grade CaCO3, but similar to the ENV of commercially available liming materials. The DFGD by-product was as effective as reagent-grade CaCO3 at raising soil pH when incubated at a rate equivalent to the soil’s lime requirement and more effective than reagent-grade CaCO¬3 when incubated at 2x the soil’s lime requirement. Seasonal flow-weighted mean Ni concentrations and seasonal V loads were 44.5 and 86.9%, respectively, greater (P < 0.05) when amended compared to the unamended control during at least one season. One month after application, aboveground dry matter and tissue As, Se, Cr, Co, Hg, V, and U concentrations were between 53 and 471% greater in the amended treatment than in the unamended control. Trace element concentrations decreased to pre-application levels within six months. Results demonstrated that the high-Ca DFGD by-product used in this study is a viable liming material and has minimal effects on runoff and plant quality when applied at a rate of 9 Mg ha-1. Consequently, land application of high-Ca DFGD by-products may be a viable alternative to current disposal methods.